package org.shop.controller.pay.util;

import java.security.MessageDigest;
import java.util.Iterator;
import java.util.Map;
import java.util.Random;
import java.util.Set;
import java.util.SortedMap;

import org.shop.controller.pay.MD5Util;

/*
 * '============================================================================
 * 'api说明：
 * 'createSHA1Sign创建签名SHA1
 * 'getSha1()Sha1签名
 * '============================================================================
 * '
 */
public class Sha1Util {
	
	public static String getNonceStr() {
		Random random = new Random();
		return MD5Util.MD5Encode(String.valueOf(random.nextInt(10000)) , "UTF-8");
	}
	
	public static String getTimeStamp() {
		return String.valueOf(System.currentTimeMillis() / 1000);
	}
	
	// 创建签名SHA1
	public static String createSHA1Sign(SortedMap<String , String> signParams) throws Exception {
		StringBuffer sb = new StringBuffer();
		Set<Map.Entry<String , String>> es = signParams.entrySet();
		Iterator<Map.Entry<String , String>> it = es.iterator();
		while (it.hasNext()) {
			Map.Entry<String , String> entry = it.next();
			String k = entry.getKey();
			String v = entry.getValue();
			sb.append(k + "=" + v + "&");
			// 要采用URLENCODER的原始值！
		}
		String params = sb.substring(0 , sb.lastIndexOf("&"));
		System.out.println("sha1 sb:" + params);
		return getSha1(params);
	}
	
	// Sha1签名
	public static String getSha1(String str) {
		if(str == null || str.length() == 0) {
			return null;
		}
		char hexDigits[] = {'0' , '1' , '2' , '3' , '4' , '5' , '6' , '7' , '8' , '9' , 'a' , 'b' , 'c' , 'd' , 'e' , 'f'};
		
		try {
			MessageDigest mdTemp = MessageDigest.getInstance("SHA1");
			mdTemp.update(str.getBytes("UTF-8"));
			
			byte [] md = mdTemp.digest();
			int j = md.length;
			char buf[] = new char [j * 2];
			int k = 0;
			for(int i = 0 ; i < j ; i++) {
				byte byte0 = md[i];
				buf[k++] = hexDigits[byte0 >>> 4 & 0xf];
				buf[k++] = hexDigits[byte0 & 0xf];
			}
			return new String(buf);
		} catch (Exception e) {
			return null;
		}
	}
}
